EVAL is a widely used yet frequently misunderstood SAS macro language function due to its seemingly simple form. However, when its actual argument is a complex macro expression interlaced with special characters, mixed arithmetic and logical operators, or macro quotation functions, its usage and result become elusive and problematic. In this paper, we aim to explore and demystify the intricate ...

Abstract Hydrocarbon exploration has long been based on such costly and time-intensive methods as geophysical surveys, geological studies, drilling. In recent years, however, researchers have started to consider inexpensive alternatives surface geochemistry for hydrocarbon exploration. Some 100 years ago, the leakage of hydrocarbons onto in form micro- macro-seepages motivated toward drilling a...

Shale oil and gas are currently the major fields of unconventional hydrocarbon exploration development. The Fengcheng Formation (FF) shale in Mahu Sag Junggar Basin is an alkaline lacustrine organic-rich with extremely prospective potential. However, its strong heterogeneity complex pore structure greatly influence development oil. It significant to investigate geochemical characteristics reser...

Transforming text into executable code with a function such as JavaScript’s eval endows programmers with the ability to extend applications, at any time, and in almost any way they choose. But this expressive power comes at a price. Reasoning about the dynamic behavior of programs that use this features becomes difficult. Any ahead-of-time analysis, to remain sound, is forced to make pessimisti...

The ever-increasing demand for oil and gas has driven its exploration in rather extreme conditions. In Lamu offshore, which is hitherto underexplored, most of the wells already drilled turned out dry save a few with hydrocarbon shows despite promising reservoir properties related geological structures. This, therefore, necessitated source rock evaluation study area to ascertain presence potenti...

This paper reports on the elemental geochemistry of 47 shale samples from uppermost Hirnantian–lowermost Rhuddanian Tanezzuft Formation, collected drill core (depth interval 20.8–73.2 m) borehole JA-2 at eastern Kufra Basin, SE Libya. Eighteen these were also analysed by X-ray diffraction. study was carried out (i) to search for shales with high total organic carbon (TOC >3 wt%) and associated ...

ion and function application employ the notion of substitution. Recall the inference rule and its representation in LF: e1 ↪→ lam x. e1 e2 ↪→ v2 [v2/x]e1 ↪→ v ev app e1 e2 ↪→ v ev app : ΠE1:exp. ΠE2:exp. ΠE′ 1:exp→ exp. ΠV2:exp. ΠV :exp. eval E1 (lam E′ 1) → eval E2 V2 → eval (E′ 1 V2) V → eval (app E1 E2) V. As before, we transcribe this (and the trivial rule for evaluating λ-expressions) into...

PURPOSE To determine physical characteristics of mixtures of ethylene vinyl alcohol copolymer (EVAL) and metrizamide dissolved in dimethyl sulfoxide, liquid materials developed for embolization of arteriovenous malformations. METHODS EVAL and dimethyl sulfoxide were mixed in various proportions and sterilized. The viscosity and density of each mixture was measured. Precipitation times were de...

Transforming text into executable code with a function such as JavaScript’s eval endows programmers with the ability to extend applications, at any time, and in almost any way they choose. But, this expressive power comes at a price: reasoning about the dynamic behavior of programs that use this feature becomes challenging. Any ahead-of-time analysis, to remain sound, is forced to make pessimis...